DE 10238664 A1 discloses a drive assembly with a starting element which is connected on the input side to the driven side of a vehicle, which forms a crankshaft axle and is connected on the output side to a speed changing gear. The output shaft of the speed changing gear is located on the same side as the input shaft and runs essentially parallel to it. By way of a subsequent gear stage a lateral offset is achieved so that the output shaft has a greater distance to the crankshaft axle than the input shaft. A front axle differential whose driven shaft runs between the engine and starting element is connected to the output shaft of the subsequent gear stage.
The disadvantage is that a gear for continuously variable transmission of torque in a variator design cannot be connected to this drive assembly, since, for design reasons, a very large amount of installation space is lost in this way. Furthermore, it is not possible to provide this drive assembly with a variator and at the same time to implement a center arrangement on the longitudinal axis of Another disadvantage is that no means are included which allow the rpm on the input shaft of the speed change gear to be changed such that it can be operated as efficiently and carefully as possible.
DE 10212790 A1 shows a speed change gear with an engine on whose driven side, which forms a crankshaft axle, two starting elements are connected. The first starting element establishes a connection to a constant transmission ratio stage which contains two transmission ratios. The second starting element establishes a connection to a third starting element by way of a shaft which runs in a hollow shaft. The third starting element is connected on the output side to a preliminary gear stage whose output shaft has a lateral offset. The output shaft of the preliminary gear stage leads to an input-side disk set of the variator. An output-side disk set of the variator is connected to an optional clutch. On the output shaft of the clutch there are three gears, two of them being the initially described gears of the constant transmission ratio stage. The third gear is connected to the third starting element and is used to reverse the direction of driving. A front axle differential whose driven shafts run between the engine and the first starting element is connected to the output shaft of the gear which is the last one viewed from the clutch.
The disadvantage is that the variator for reasons of design has a lateral offset which leads to the illustrated speed change gear not being able to be placed in the middle on the longitudinal axis of the vehicle, as a result of which the leg room in the passenger compartment is greatly limited. Furthermore, this arrangement leads to a large amount of installation space being required. Another disadvantage is that it is not possible to adapt the rpm which has been changed on the input side by the preliminary gear stage of the variator on the output shaft of the variator again such that the potential of the variator can be fully used, with simultaneous gentle operation.
The object of this invention is therefore to make available a power train which with a variator ensures continuously variable transmission of torque and takes up little installation space in doing so, and implements simple rpm matching to vehicles with different engines and weight.